RIC-0090 Number Grids

1. Several squares have been drawn on the
1–100 grid. Try multiplying the numbers
diagonally opposite each other.
(a) 12 x 23 = ,
13 x 22 =
(b) 35 x 46 = ,
36 x =
(c) 52 x = ,
x =
(d) x = ,
x =
(e) x = ,
x =
2. What do you notice about the answers?
Four Squares
1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
51 52 53 54 55 56 57 58 59 60
61 62 63 64 65 66 67 68 69 70
71 72 73 74 75 76 77 78 79 80
81 82 83 84 85 86 87 88 89 90
91 92 93 94 95 96 97 98 99 100
3. Investigate what happens when you draw squares that are 3 cells by 3 cells.
(a) x =
1 2 3 4 5 6 7 8 9 10
x =
11 12 13 14 15 16 17 18 19 20 (b) x =
21 22 23 24 25 26 27 28 29 30
x =
31 32 33 34 35 36 37 38 39 40 (c) x =
41 42 43 44 45 46 47 48 49 50
x =
51 52 53 54 55 56 57 58 59 60
(d) x =
61 62 63 64 65 66 67 68 69 70
x =
71
81
72
82
73
83
74
84
75
85
76
86
77
87
78
88
79
89
80
90
4. What do you notice about the
answers?
91 92 93 94 95 96 97 98 99 100
5. Try investigating 4x4 squares.
What do you notice?
1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
51 52 53 54 55 56 57 58 59 60
61 62 63 64 65 66 67 68 69 70
71 72 73 74 75 76 77 78 79 80
81 82 83 84 85 86 87 88 89 90
91 92 93 94 95 96 97 98 99 100
R.I.C. Publications www.ricgroup.com.au
61
Number Grids
ISBN 978-1-86311-826-2